The invention concerns a fleece funnel, which is placed at a predetermined distance behind exit rolls of a stretch works of a textile machine, the latter being, in particular, a carding machine. One longitudinal side of the fleece funnel is closed off laterally by a baffle plate, and borders a bulged out impact plate. At the deepest part of the bulged impact plate, a boring is provided for the reception of a funnel outlet duct. The impact surface forms an intersection line with a ramp plate opposite to the baffle plate.
In the practice, the fleece funnel would also be called a xe2x80x9cmatting nozzlexe2x80x9d. For the sake of a consistent terminology, the term xe2x80x9cfleece funnelxe2x80x9d will be used in the following.
DE 196 18 642 A1 discloses a fleece funnel. The fleece funnel therein described should clearly assure a higher delivery capacity than 900 m/min without interfering with the quality of the fiber band and without disturbance to the fiber band transport.
In the technical development of the stretch machine, an increase of the through-put speed was given high rank as a requirement. To this point, we make a few comments:
As a rule, a plurality of fiber bands are fed to the stretch works of a stretch machine, which are combined into a single fiber band. The tensioning of the doubled fiber band was carried out in a stretch works. The delivery roll-pair is the exit roll-pair of a stretch works and produces a widened out fiber band. The widened fiber band is designated by the expert in the operation as xe2x80x9cFiber mattingxe2x80x9d. This fiber matting is transported into the fleece funnel at a high velocity ( greater than 900 m/min). The speed of this delivery is transmitted to the fiber matting by means of the circumferential speed of the delivery roll-pair. The fleece funnel must collect this fiber matting, roll it up, so that the air is expelled from the fiber matting, and divert it to the funnel outlet duct from whence it is discharged.
With the feed of the fiber matting into the receiving opening of the funnel, there arises once more a thickened fiber band. The previous developments concerning such funnels showed widely differing presentations of design.
By means of the high delivery speed (up to 1000 m/min) in the stretch machine, the shape of the fleece funnel intensively occupied the designers. In this activity, it was shown that the fleece funnel, along with other operational organs, played an essential role for the attainment of the desired delivery speed. The fleece funnel must be in such a technological state, that in the case of essentially higher speeds of the transported matting received from the delivery rolls, this matting could be safely rolled out without detracting from the quality, and further transported as a fiber band.
These described fleece funnels were also used on stretch works on which a carding machine had been added. In this case, the evidence showed that the fleece funnel, laid out for high delivery speeds of the fiber band, allowed no automatic entry manipulations to permit a fiber band of a carding machine to enter into the said fleece funnel. The delivery velocity of the fiber band in carding machines runs between 150 m/min to 180 m/min.
It is the purpose of the invention to design a fleece funnel for a stretch machine in such a manner that the fiber band being delivered from the stretch works be automatically transported into the fleece funnel at a lower speed and without manual intervention. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
The invention concerns a fleece funnel, which is placed at a predetermined distance behind exit rolls of the stretch works of a textile machine, the latter being especially, a carding machine. One longitudinal side of the fleece tunnel is closed off laterally by a baffle plate and borders a bulged out impact plate. At the deepest part of the bulged impact plate, a boring is provided for the reception of a funnel outlet duct, and the impact plate forms an intersecting line with a ramp plate located opposite to the baffle plate.
In accord with the invention, from any chosen point of the common line of intersection of the impact plate and the ramp plate, the impact plate exhibits a decline to the discharge of the funnel duct. In other words, the intersection forms an apex line, or a kind of a crest, which is created from both sides, i.e. the ramp plate on one side and the impact plate on the other, each built with a downward slope. By means of the additionally sloped impact plate, the fiber band being delivered from a stretch works, that is the beginning of the fiber band, is guided automatically to the feed opening of the funnel. The insertion of the fiber band is done, in this operation, entirely automatically.
Following the passage of the fiber band start through a (as a rule) closed stretch works, the fiber band start strikes the impact plate and slides, without any assisting manipulation, directly to the exit connection of the funnel, i.e. the funnel duct. The manual guidance of the fiber band into the funnel, employed up to this time, can now be left to automatic means. Upon the start-up of the textile machine, the fiber band is first introduced into a closed stretch works and from the stretch works, automatically directed to the fleece funnel. At this point, in an appropriate manner, the fiber band at its start is somewhat twisted, so that a front running, tapered point is formed. This front running fiber band head enables an additionally easy introduction of the fiber band into the stretch works and into the fleece funnel.
Further, it is advantageous , if between the impact plates and the baffle plates an intersecting line is so formed, that from each point of this line of intersection to the funnel outlet duct, the impact plate is again, likewise provided with a declining aspect. This leads to the situation, that, as a whole, a funnel-like funnel, i.e. a conical shaped funnel impact surface is formed, so that the fiber band start is conducted to the funnel exit duct both from the baffle plate and the bordering impact plate.
In an improvement, the intersecting lines touch one another in such a manner, that they become continuous, that is, take form all around the periphery of the outer rim of the impact plate. By this means, in effect a common intersection line is formed.
An easy sliding of a fiber band is especially assured if the two intersection lines in the common contact points exhibit the same curvature.
Even so, it is possible that the ramp plate side impact plate and the oppositely situated baffle plate, in their common contact line, form a fissure or a groove. Preferably, the transition is to be smooth and without recesses or the like.
The fleece funnel can be made out of one piece, if, a conical or cone shaped funnel-form is made from the peripherally running intersection line to the rim of the outlet duct of the funnel. By means of this shape of the funnel, no edges or rough seams evolve, so the fiber band is particularly well conducted from the side areas of the funnel to the exit duct thereof.
The sliding of the fiber band beginnings, that is, the entire fiber band, is further enhanced by the fact that the impact plate has a smooth and/or exhibits a polished surface. By such smooth surfaces, the friction coefficient and the friction between the fiber band and the impact plate is clearly reduced, whereby the fiber band can be quickly and easily automatically manipulated.
A further improvement of the automatic insertion of the fiber band into the funnel is achieved in that, as seen in a cross-section view, in respective planes perpendicular to the baffle plate, the intersection point proximal to the baffle plate is lower, in relation to the outlet opening of the funnel, than is the corresponding intersection point remote from the baffle plate. This means that the ramp side intersection line is, in general, always, xe2x80x9chigherxe2x80x9d than is the corresponding intersection on the impact plate. In general, the inclined impact plate on the baffle plate side is bordered by the baffle plate, which rises above the opposite impact surface. When the entering fiber band strikes the baffle plate, then the fiber band will be diverted onto the impact plate and conducted without problem from there into the funnel exit duct as a result of the designed impact plate slope.
Favorable relationships to the automatic, insertion of the fiber band into the funnel arise when the opening angle formed between the longitudinal axis of the funnel outlet duct and the plane of the impact plate surface varies between 10xc2x0 and 75xc2x0. This opening angle assures a reasonable compromise between the funnel like receiving surfaces and the inclination of the surfaces, which, with an increasing opening angle, assure that the friction will be reduced.
If the angle is set at too great a value, then the receiving surface is clearly reduced, whereby the automatic entry is made difficult. When the receiving surface is larger, then the fiber band point is more easily captured. Moreover, on the fleece funnel, advantageously, the opening angle of the impact plates are symmetric to a plane vertical to the longitudinal axis of the funnel exit duct and the baffle plate. In this way, the construction is substantially simplified.
Summarizing, the invention makes possible an easy and reliable insertion of a fiber band point into a fleece funnel. Besides this, the fiber band entry is carried out automatically and without manual help. For the support of the introduction of the fiber band point, a pneumatic suction can be provided. In order to increase the density, or thicken, the fiber band, customarily, the funnel exit diameter is less than the thickness of the fiber band. For the insertion, in any event, the fiber band is provided with a point at its start, that is, as mentioned, by twisting the fiber band. As an alternative fraying or thining out the fiber band is likewise a possibility.
With the aid of the following drawings, embodiments of the invention are more closely described and explained.